Variable velocity weapons having selective lethality and methods related thereto

Abstract

The present invention relates to weapon systems that accelerate projectiles using gases generated by the rapid combustion of a solid propellant, in particular, such a weapon system is able to vary the barrel exiting velocity of the projectile through a barrel venting means. In one embodiment, a front venting means exhausts gas generated by combusting propellant from behind the accelerating projectile and redirects a portion of the exhausted gas either to at least one fixed volume, to the front of the projectile, or to a combination of at least one fixed volume and to the front of the projectile. Redirecting some of the exhausted gas to the front of the projectile restrains the projectile, thereby slowing the projectile, and thus further decreasing the muzzle velocity of the projectile. In another embodiment, gas from behind the projectile is exhausted into a fixed volume, thereby decreasing projectile acceleration, and thus, the muzzle velocity of the projectile. One can use a combination of fixed volume venting and front venting. A saboted projectile can be used for ammunition. By coupling the energy requirements needed to release the sabot to the barrel exiting velocity of the projectile, one can achieve a selectively lethal projectile. The venting means can be variable as to the velocity and mass of propellant gases exhausted or redirected and can be coupled to an operator selection switch, as well as to an automatic range finding scope.

We claim: 
     
       1. A method for firing a projectile comprising: a) loading a cartridge with a saboted projectile into a barrel having a breech end for receiving the cartridge with the saboted projectile and a muzzle end for discharging the saboted projectile, the saboted projectile comprising a penetrator surrounded by a sabot which is configured wherein the ballistic coefficient of the saboted projectile is less than 0.1 and the diameter is at least fifty percent greater than the projectile diameter;   b) creating propellant gases behind the projectile so as to accelerate the saboted projectile toward the muzzle end of the barrel; and   c) lowering the muzzle velocity of the saboted projectile to at least less than one-half the maximum muzzle velocity for the saboted projectile by venting the propellant gases from the barrel into a non-atmospheric vent volume at a predetermined venting rate.   
     
     
       2. A weapon system having a reduced lethality projectile comprising: a) a barrel for firing a cartridge having a saboted projectile using propellant gases, having a breech end for receiving the cartridge and a muzzle end for discharging the saboted projectile;   b) the saboted projectile comprising a penetrator surrounded by a sabot which is configured wherein the ballistic coefficient of the saboted projectile is less than 0.1 and the diameter is at least fifty percent greater than the projectile; and   c) a means for venting the propellant gases from the barrel at a predetermined venting rate into a non-atmospheric vent volume which is disposed about the barrel and has at least one opening in communication with the barrel, wherein the venting means lowers the muzzle velocity of the projectile to at least less than one-half the maximum muzzle velocity for the saboted projectile.   
     
     
       3. A weapon system having a variable velocity comprising: a) a barrel for firing a cartridge having a projectile using propellant gases, having a breech end for receiving the cartridge and a muzzle end for discharging the projectile;   b) a means for venting the propellant gases from the barrel, the venting means being disposed about the barrel and configured to direct propellant gases which are behind the projectile, as the projectile starts to move from the breech end to the muzzle end, into a non-atmospheric, fixed vent volume, thereby reducing the accelerating force on the projectile; and   c) a means for creating propellant gases behind the projectile which accelerate the projectile toward the muzzle end of the barrel, imparting a muzzle velocity to the projectile, wherein the opening of the venting means lowers the muzzle velocity of the projectile from a maximum muzzle velocity that is achieved if the venting means is not open.